Androgenic hormones (testosterone and dihydrotestosterone) stimulate sexual differentiation and development as well as the maintenance of male reproductive function. Androgens exert a major influence on gene expression in target tissues, however, the mechanisms by which they stimulate nucleic acid and protein synthesis remain unknown. The objective of this research is to define mechanisms by which androgens control gene expression. This will be accomplished by studies on the regulation of genes coding for the 3 subunits of prostatein, the major secretory protein of the rat ventral prostate and the 20K protein, another major androgen dependent protein. The androgen receptor recognition sequence (ARRS) will be identified by binding of partially and highly purified androgen receptor preparations to short segments of genomic DNA. ARRS will be mapped across the genes and their flanking DNA. Structural features of the gene regions surrounding receptor binding sites will be identified by DNA sequencing. The relationship of putative promotors or enhancers to ARRS will be established by mapping the DNAse I hypersensitive sites within and adjacent to prostatein genes. It will determine whether androgen receptors have a role in gene attachment to nuclear matrix. The androgen regulated genes will be cloned in eukaryotic expression vectors and transferred to androgen responsive primary cultures of ventral prostate epithelial cells and well differentiated epithelial cell lines for studies on the regulation of gene expression. Deletion mutants will be constructed to identify promotor and possible enhancer elements in androgen regulated genes. The interaction among androgen receptors and other regulatory proteins will be investigated using subcloned ARRS and promotor sequences as probes for sequence-specific DNA binding proteins. It is expected that the information derived from these studies will provide new insight into androgen regulation of male reproductive function and will be revelent to the problems of infertility and fertility control.